charlatan

Whether to convince others or me, I can pretend to be somewhat smart and adept.
But, reality ever seems to find ways to throw itself into my face and reminds me of who I am.
A lousy impersonator, I always have been and always will be.

What you imply: that you are not REALLY smart and adept — this is SO not true. Of course, everything (and everyone) is relative. There are people very much smarter and more adept than you; there are people far less so. But you are definitely WAY above average. And you can trust my judgment, because I am very smart and very adept, and I say you are, too.